Shoulder/scapula Flashcards
Scapulohumeral (intrinsic shoulder) muscles
deltoid, supraspinatus, infraspinatus, teres minor, teres major, subscapularis
Attachments of deltoid
Proximal: lateral third of clavicle, acromion and spine of scapula
Distal: deltoid tuberosity of humerus
Innervation of deltoid
axillary nerve (C5, C6)
Action of deltoid
anterior: flex and medially rotates arm
acromial (middle): abducts arm
posterior: extends and laterally rotates arm
Attachments of supraspinatus
Proximal: supraspinous fossa of scapula
Distal: superior facet of greater tubercle of humerus (via strong flat tendon)
Innervation of supraspinatus
suprascapular nerve (C5, C6)
Action of supraspinatus
initiates (first 15 degrees) and assists deltoid in abduction of arm and acts with rotator cuff
Attachments of infraspinatus
Proximal: infraspinous fossa of scapula
Distal: middle facet of greater tubercle of humerus
Innervation of infraspinatus
suprascapular nerve (C5, C6)
Action of infraspinatus
laterally rotates arm and helps hold humeral head in glenoid cavity of scapula, acting with rotator cuff
Action of teres minor
laterally rotates arm and acts with rotator cuff
Attachments of teres minor
Proximal: middle part of lateral border of scapula
Distal: inferior facet of greater tubercle of humerus
Innervation of teres minor
axillary nerve (C5, C6)
Attachments of teres major
Proximal: posterior surface of inferior angle of scapula
Distal: medial lip of intertubercular sulcus of humerus
Innervation of teres major
lower subscapular nerve (C5, C6)